The invention relates to a method in apparatus for acting upon cloth. While the invention is applicable to a wide variety of different procedures in operation, the primary focus of the invention is on the completely automatic production of shirt sleeves from a sleeve blank, particularly the formation of sleeves for T-shirt.
In the past, the commercial production of shirt sleeves, particularly T-shirt sleeves has been quite labor-intensive and expensive. A sleeve blank is cut from a larger piece of cloth, and then is fed by hand to to a forming station whereat a hem is formed along one edge of the blank. The hem blank is then commonly manually removed from the forming station, folded over by hand, and passed by hand under an automatic sewing machine to form an arcuate seam along an edge of the blank generally transverse to the hem. Since many more sleeve blanks can be hemmed per unit time by the formation station than can be seamed, usually two or three workers are necessary to effect seaming for each forming stations. This results in the sleeve formation operation being very labor-intensive and relatively expensive, and a substantial floor area is required to accommodate the necessary workers and machinery.
According to the present invention, a method and apparatus are provided that eliminate the drawbacks inherent in conventional commercial T-shirt sleeve production. According to the present invention, a single apparatus which takes up very little more floor space than a conventional forming station-automatically hems and seams a T-shirt sleeve blank to produce a complete T-shirt sleeve. Only a single operator is necessary, and production is as good, or perhaps even better, than is achieved at conventional forming stations also with a single operator.
According to one aspect of the present invention, a method of automatically forming a shirt sleeve from a sleeve blank is provided. The method comprises the steps of sequentially: (a) Conveying the blank in a first direction so that a first edge thereof moves substantially parallel to the first direction. (b) Automatically forming a hem along the first edge. (c) Automatically picking up the hemmed sleeve blank and folding it about an axis substantially transverse to the first edge. (d) Conveying the folded, hemmed blank in a second direction substantially transverse to the first direction, so that a second edge thereof is generally parallel to the second direction. And, (e) automatically stitching along the second edge to stitch overlapped portions of the folded blank together to form a shirt sleeve.
Between steps (b) and (e) the hem is automatically ironed so that it lays substantially flat. The second edge of the double-over hemmed blank conventionally has an arcuate portion, and according to the invention the blank is acted upon to move the second edge thereof in an arcuate manner, generally coincident with the arcuate portion of the second edge, as it is being acted upon by an automatic sewing machine, the stitching being practiced by forming a trimmed seam along the second edge.
The invention also comprises apparatus for practicing the method heretofore described. In fact that invention contemplates an assembly for acting upon cloth in general. The assembly includes a first conveyor disposed for conveying cloth generally horizontally in a first direction, and a first automatic sewing machine operably disposed alongside of the first conveyor for acting upon cloth being transported by the first conveyor. A second conveyor disposed generally at the end of the first conveyor, in the first direction, and disposed for conveying cloth generally horizontally in a second direction substantially transverse to the first direction. Means are operably mounted at an interface between the first and second conveyors for automatically transferring cloth from the first to the second conveyor; and a second automatic sewing machine is operably disposed alongside of the second conveyor for acting upon cloth being transported by the second conveyor.
A component part of the apparatus heretofore describe which is applicable to many procedures for acting upon cloth, or other objects, includes an assembly for picking up the objects off of an operating conveyor. The assembly includes a conveyor including a plurality of distinct, substantially parallel conveying portions, and a plurality of stationary surfaces interleaved with, and substantially parallel to, the conveying portions. Means are provided for mounting the conveying portions for movement from a first position to a second position. In the first position, the conveying portions are raised with respect to the stationary surfaces so that objects being transported by the conveying portions are transported over the stationary surfaces without touching them. In the second position, the conveying portions are depressed with respect to the stationary surfaces so that objects being transported by the conveying portions come in contact with the stationary surfaces and are no longer transported by them. Pickup means are provided for picking objects off of the stationary surfaces when objects are supported thereby, and means are provided for automatically moving the conveying portions from the first to the second positions thereof in responnse to the pickup means moving into operable association with objects being conveyed by the conveyor.
Another subassembly according to the present invention which has wide applicability for automatically effecting non-linear stitch formation in cloth comprises the following components:
A. conveyor for conveying the cloth in a predetermined linear direction. A stitching mechanism mounted in operable association with the conveyor for effecting stitch formation in cloth as it is being transported by the conveyor in the predetermined linear direction. And a differential-speed-cloth-engaging means for automatically engaging a portion of the cloth remote from the stitching mechanism, while the cloth is still being conveyed in the predetermined linear direction, an effecting movement of the cloth so that a portion of the cloth adjacent the stitching mechanism moves in a non-linear path as the cloth is being transported by the conveyor past the stitching mechanism. The conveyor preferably comprises a plurality of space conveyor belt portions, while the differential-speed-cloth-engaging means comprises a speed roller spaced from the stitching mechanism and rotatable about a horizontal axis perpendicular to the predetermined linear direction. The roller is rotated so that the cloth-engaging periphery thereof has an effective speed greater than the conveyor speed, which causes the arcuate movement of the cloth.
The invention also contemplates a hot wire cutter that is capable of simultaneously cutting the stitching formed by an automatic sewing machine after a cloth article is stitched, and fusing synthetic thread used during stitching so that no perceptible nub extends from the article.
It is primary object of the present invention to provide a method and apparatus for automatically acting upon cloth, and particularly for automatically forming T-shirt sleeves from sleeve blanks. This and other objects of the invention will become clear from the inspection of the detailed description of the invention, and from the appended claims.